The invention relates to a counter, particularly for liquid meters, which includes a first number wheel that can be driven by a drive shaft and is provided for values of a low decade. With this first number wheel are associated further number wheels for values of higher decades and an additional number wheel for values of a lowest decade. The driven first number wheel and the additional number wheel are each provided with an alignment star with which a corresponding pawl is brought into engagement for aligning the number wheel by a cam control mechanism when a handle is operated.
A counter of this kind is disclosed in German Patent 926,049 wherein, upon rotation of the drive shaft, only the number wheel for a low decade which can be driven by the drive shaft, and if applicable, further number wheels for values of higher decades are driven. An additional number wheel for values of a lowest decade remains in the rest position. Only when the drive shaft has come to a standstill (in the case that the known counter is connected with a liquid meter, this will be as a rule when a given quantity of liquid has been delivered), is a gear drive brought into engagement with the driven number wheel as well as with the additional number wheel through the operation of a handle. In addition, pawls drop into alignment stars of the driven number wheel and of the additional number wheel, this action being caused by a cam control mechanism when a handle is operated. Consequently, an alignment of the two number wheels is achieved in such a manner that they assume a position suitable for printing, which is such that after alignment, the individual numerals on the number wheels are in one line and therefore give a readable printout upon printing.
This known counter presents difficulties insofar as, after the driven number wheel is set by the drive shaft, a setting of the additional number wheel corresponding to the intermediate values at the driven number wheel must be accomplished in the alignment in a very short time by the operation of the handle. Large accelerations therefore occur in the alignment. In order to avoid damage to the mechanical parts, they must be made of relatively high-quality material, which causes a not inconsiderable extra expenditure.
Similar difficulties are encountered in the manufacture of another printing counter (German Patent 1,144,957) wherein an indicating number wheel that rotates the fastest sets a printing cylinder associated with it, which serves to print out the value of the integral numbers on the one hand accordingly, and on the other hand, drives an alignment mechanism which at first is idling along, at a fraction of the 1:10 transmission required overall. Although this counter is advantageous in view of the loading of a measuring device connected through the drive shaft, because it needs to supply only a relatively small torque for setting the counter due to the initially idling-along alignment mechanism, the problems already described above require relatively expensive materials also in this counter so that the manufacture also of this known counter becomes relatively expensive.
It is therefore an object of the invention to provide a counter wherein the alignment of the number wheels for the purpose of a clear readout of the counter setting is achieved also with regard to the values of the lowest decade notwithstanding the use of relatively inexpensive materials such as plastics.